THE CLINICAL RESEARCH CORE will support the acquisition of specimens for hypothesis-driven pathogenesis-based studies through recruitment and management of HIV-1-infected individuals with well-defined clinical and laboratory profiles enrolled in NIH-sponsored natural history and therapeutic trials for: intensive, systematic sampling of blood, cerebral spinal fluid, genital secretions and lymphoid tissue; meticulous specimen processing; and the repository storage and inventory of these samples under appropriate conditions. The resources for the Clinical Research Core will not overlap with or substitute for the support of the AIDS Clinical Trials Group (ACTG) or Multicenter AIDS Cohort Study (MACS) related therapeutic trials or protocols, or the required routine sampling of blood obtained from the enrolled subjects during the course of these or other sponsored studies. The Clinical Research Core will support novel therapeutic trials for anti-retroviral combination therapies and gene therapy supplemented by intensive, systematic sampling of blood and tissue from highly selected participants in these NIH-sponsored studies who have a history of well-defined clinical and laboratory data and the repository of well-characterized clinical specimens. All specimen collection and transfer within and between institutions will be conducted in accordance with all applicable ordinance and regulations to ensure basic health and safety standards. Dr. John Phair of Northwestern University will be the director of the Clinical Research Core and will oversee al clinical research activities with the goal to synergistically coordinate the activities and needs of the CFAR investigators. Drs. Henry Balfour and Robert Murphy will be co-directors of the Clinical Research Core at Northwestern University and the University of Minnesota, respectively. The Clinical Research Core will design, develop and implement anti-retroviral and gene therapy protocols in collaboration with the initiating center investigators, the Biostatistics Core and the Pharmacology Resource Unit, the latter under the direction of Drs. Courtney Fletcher and Lester Drewes of the University of Minnesota. Dr. Charles Bennett of Northwestern University will be responsible for determining outcome measurements.